Experimental elucidation of dynamic behaviors to facilitate protein functions

2014 Fiscal Year Final Research Report

• Project/Area Number: 23750015
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Physical chemistry
• Research Institution: Osaka University
• Principal Investigator: MIZUNO Misao 大阪大学, 理学(系)研究科(研究院), 助教 (10464257)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: 共鳴ラマン分光法 / 時間分解分光法 / 微生物型ロドプシン / タンパク質ダイナミクス / 光異性化

Outline of Final Research Achievements

Microbial rhodopsins function as either light-driven ion pumps or photosensors. In this study, structural dynamics of microbial rhodopsins were revealed by time-resolved resonance Raman spectroscopy. First, protein responses to photoisomerization of the retinal chromophore in the picosecond regime were investigated. Spectral changes in the ultraviolet resonance Raman bands due to the tryptophan and tyrosine residues in the vicinity of the chromophore were observed. It was found that the rates of primary protein response to the chromophore isomerization are similar among the rhodopsins. Second, temporal evolutions of the chromophore structure after nanoseconds were investigated by visible resonance Raman spectroscopy. For ion pumps, we revealed the structural changes of the hydrogen-bond network around the retinal chromophore which facilitate the ion pumping.

Free Research Field

時間分解振動分光学